带转换层的短肢剪力墙抗震分析

结合工程实例,运用ETABS对带转换层的短肢剪力墙进行了数值模拟,并介绍了其计算原理及计算过程,得出一些带转换层的短肢剪力墙在地震作用下的受力特性,以满足剪力墙的抗震要求。     

桉木蔗渣混合浆的漂白

采用双氧水通过生产性试验 ,说明了 CEPH漂白工艺流程用于漂白桉木 -蔗渣混合浆的有效性、可行性 ,解决了桉木浆难漂问题。     

集水坑开挖导致边坡变形的原因及处理方案

对元亨苑二期1号楼基坑支护工程中集水坑开挖导致变形进行分析，通过FLAC软件对边坡变形进行数值分析，探讨集水坑开挖导致边坡变形的原因，并提出相应的处理方案。     

碳纤维布在多层混凝土框架柱加固中的应用

碳纤维布加固混凝土结构具有不破坏原结构 ,施工方法简便 ,加固后能使结构满足设计要求等优点 ,重点介绍碳纤维布加固混凝土柱的施工工艺及施工验收     

水基浆料涂覆结合原位反应制备Cf/SiC复合材料表面光学涂层

本研究提出一种C_f/SiC复合材料表面改性新方法为水基浆料涂覆结合原位反应烧结工艺。系统研究了SiC和炭黑在水基浆料中的共分散、粘结剂的量和浆料固含量对浆料流变性能的影响、涂层的微观结构和性能等。研究结果表明: 采用水基浆料涂覆工艺可在基材表面制备一层气孔率达49%的多孔C/SiC预涂层; 通过液相渗硅原位反应工艺, 多孔预涂层转变为高致密、与基材强结合的光学涂层, 并且在涂层与基材间形成了~ 15 μm的化学反应过渡层; Si/SiC涂层的维氏硬度为(14.19 ± 0.46) GPa, 断裂韧性为(3.02 ± 0.30) MPa·m^1/2; 经过精细研磨抛光, 涂层的表面粗糙度可达2.97 nm RMS。     

采用碳纤维布对混凝土框架柱补强

碳纤维布补强砼结构是一种新兴的科技含量较高的加固手段,主要应用于补强混凝土梁与板。它具有不破坏原结构,施工方法简便,加固后能使结构满足设计要求.虽然这种加固方法其材料价格相对较高,但与其他加固方法相比,可节约施工费用,并且加固完成后,结构在使用过程中无需再投入维护费用,使用寿命长,这种加固方法具有长远的综合效益。本文重点介绍碳纤维布加固砼柱的施工工艺及施工验收。     

Sintering kinetics of YAG ceramics

Solid state reactive （SSR） sintering kinetics was observed for YAG ceramics. There were two densification stages in sin- tering process due to its reaction. After the first stage, samples began to expand, then, the second densification stage began. At a heat- ing rate of 10 ℃/min, the sample warped down and warped back to straight. The apparent activation energy of the first densification process was about 522 kJ/mol for the initial shrinkage of A1203 and Y203 mixed powder green-body, which increased in the follow- ing process due to the solid state reaction. In the second densification stage, synthesis reaction of YAG still worked. Green-bodies processed with higher heating rate got more shrinkage at the same temperature than lower heating rate green bodies. And its kinetic field diagram was abnormal, compared with that of other reported ceramics, such as Al203. It was found that the reaction of YAG provided positive effect to the sintering driving force. The apparent activation energy for densification of SSR YAG sintered in ArH5 atmosphere was 855 kJ/mol at temperature holding sintering. And the apparent activation energy for grain growth was 1053 kJ/mol.     

松软煤层深孔预裂爆破力学特性的数值分析

 煤层深孔预裂爆破近年来在瓦斯抽放中运用日益增多,但目前对其爆破理论研究较少。以矿井现场实际使用的爆破、炸药和煤层参数为基础,利用三维数值模拟方法进行煤层预裂爆破机制研究。建立柱状药包爆破数值计算模型,研究煤体破坏单元的范围和受爆破应力波作用的抽放影响区域。研究结果表明,爆破粉碎范围最大接近40 cm,爆破对抽放量影响的作用半径不超过10 m,其中以4 m内变化最明显。探讨不同距离抽放孔有效应力传播特点,研究中首次考虑因导爆索与乳化炸药传爆速度不同造成的煤层中应力分布差异,澄清了认识上的误区。分析松软煤介质中不同距离抽放孔的位移场变化规律,计算结果与现场爆破前后实测的瓦斯抽放数据相吻合。研究结果对促进预裂爆破技术更好地运用于煤矿瓦斯治理是有益的。     

Sintering of transparent Nd:YAG ceramics in oxygen atmosphere

Yttrium aluminum garnet (YAG) transparent ceramics were fabricated by sintering at oxygen atmosphere. Tetraethyl orthosilicate (TEOS) was added as the sintering additive to control the grain growth and densification. Pores were eliminated clearly at temperature lower than 1700oC, while grain size was around 3 μm. The in-line transmittance was 80% at 1064 nm when samples were sintered at 1710oC. The effect of TEOS was studied in oxygen atmosphere sintering for Nd:YAG transparent ceramics. At higher temperature like 1710oC, the grain growth mechanism was solute drag, while at 1630 and 1550 oC the grain growth was controlled by liquid phase sintering mechanism. And 0.5 wt.% TEOS was the best adding content for Nd:YAG sintered in oxygen atmosphere.